Visceral leishmaniasis (VL) is a disease with high mortality in both developed and developing countries. The causative agents are the parasites Leishmania chagasi, donovani and infantum depending on geographic location. In Mediterranean countries, co-infection with HIV has become problematic and asymptomatic individuals have been shown to transmit the parasite through transfusion, in both France and Brazil. The reservoir for VL is dogs and recently U.S. foxhounds have succumbed to VL raising veterinary concerns. Tests available for early diagnosis have benefited by using the recombinant K39 antigen that is specific for active disease, but does not adequately detect asymptomatic infections. In Phase I improved diagnosis (dogs/ humans) was obtained by using K39 in combination with another recombinant antigen K26. The studies proposed here are to take advantage of this enhanced detection in a combination test for VL that would have human and veterinary applications. These studies will exploit the expertise of InBios to develop FDA approved rapid tests using a combination of Corixa Corp's K39 and K26 antigens. The studies will also benefit from a close collaboration with researchers at CDC and WRAIR and renowned consultants domestically and in developing countries and by access to their human and canine serum banks. PROPOSED COMMERCIAL APPLICATION: The proposed studies will lead to the commercialization of diagnostic tests that will aid in the early diagnosis of active and asymptomatic infections with the parasites L.donovani, chagasi, and infantum. Such test would have application in the human and veterinary fields. The worldwide market for such a test is estimated to be in excess of $10-15 million dollars based on a cost of $1.50 per test.